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Nucleation and capture of condensible airborne contaminants in an aqueous scrubbing system. [LMFBR]

Description: The fate of condensible contaminants in an aqueous scrubbing system was evaluated. Knowledge of the behavior of volatile fission product compounds is important in evaluating the effectiveness of emergency air cleaning systems proposed for use in containment systems of breeder reactor plants. When a high temperature air stream passes through a spray quench chamber, very large cooling rates occur in the drop boundary layers. These large cooling rates cause large supersaturations in airborne concentrations of condensible contaminants, and one predicts that most condensation would take place through homogeneous nucleation. The very small particles formed would agglomerate, and attach to sodium aerosol particles which would be present. In the study the overall removal efficiency of volatile fission product species (typified by NaI, SeO/sub 2/, and Sb/sub 2/O/sub 3/) in an air cleaning train (quench chamber, venturi scrubber, and fibrous bed) was theoretically evaluated. The overall removal efficiency of condensible materials was found to be lower than that for sodium compound aerosols because the freshly condensed particles would be smaller in size. For a base case, a removal efficiency of 99.97 percent was predicted for condensible materials. The fibrous bed scrubber exhibited superior particle removal characteristics for small particles compared to the quench chamber and venturi scrubber. Its removal efficiency exceeded 97 percent for even the most penetrating particle size (about 0.4 micron aerodynamic diameter). Therefore, all condensible fission products would be removed with efficiencies exceeding 97 percent.
Date: September 1, 1978
Creator: Postma, A.K. & Hilliard, R.K.
Partner: UNT Libraries Government Documents Department

Aerosol measurement techniques and accuracy in the CSTF. [LMFBR]

Description: The Containment Systems Test Facility (CSTF) provides the capability of performing large-scale aerosol behavior experiments at a scale factor of approximately 0.5 in height for a typical reactor containment building. The containment height is 20.3 m, the volume is 850 m/sup 3/, the design pressure is 5 bar, and quantities of sodium up to 1250 kg can be sprayed or spilled for sodium combustion product aerosol sources. Instrumentation is provided for characterization of the aerosol and the containment atmosphere. This paper describes the aerosol sampling techniques and instruments used in the CSTF and discusses their accuracy and reproducibility.
Date: November 1, 1979
Creator: McCormack, J.D. & Hilliard, R. K.
Partner: UNT Libraries Government Documents Department

Sodium-fire control by space isolation with nitrogen flooding: FFTF proof test F2

Description: Sodium fire protection by space isolation with nitrogen flooding was evaluated by performing a large-scale sodium fire test within a mockup of an FFTF secondary sodium system pipeway. The full scale (3350 ft/sup 3/) mockup was initially filled with air and its leak tightness set to correspond to that expected in an actual FFTF pipeway. The basis for specifying the rate of nitrogen flood gas is discussed ad the experimental verification provided. Nitrogen flooding was activated 15 minutes after the spill of 770 lb of 1100/sup 0/F sodium into a 32 ft/sup 2/ steel pan. The nitrogen flow was controlled manually at a constant rate of 60 ft/sup 3//min (STP) until the pool temperature had decreased to 370/sup 0/F. After cooldown, 87% of the spilled sodium remained in the unreacted form, demonstrating that sodium fires can be effectively controlled by the method of space isolation with nitrogen flooding.
Date: June 1, 1974
Creator: Hilliard, R.K. & Muhlestein, L.D.
Partner: UNT Libraries Government Documents Department

Air-cleaning systems for sodium-fire-aerosol control. [LMFBR]

Description: A development program has been carried out at the Hanford Engineering Development Laboratory (HEDL) with the purpose of developing and proof testing air cleaning components and systems for use under severe sodium fire conditions, including those involving high levels of radioactivity. The air cleaning components tested can be classified as either dry filters or aqueous scrubbers. Test results are presented.
Date: May 1, 1982
Creator: Hilliard, R.K. & Muhlestein, L.D.
Partner: UNT Libraries Government Documents Department

Results and code predictions for ABCOVE (aerosol behavior code validation and evaluation) aerosol code validation with low concentration NaOH and NaI aerosol: CSTF test AB7

Description: A program for aerosol behavior validation and evaluation (ABCOVE) has been developed in accordance with the LMFBR Safety Program Plan. The ABCOVE program is a cooperative effort between the USDOE, the USNRC, and their contractor organizations currently involved in aerosol code development, testing or application. The third large-scale test in the ABCOVE program, AB7, was performed in the 850-m/sup 3/ CSTF vessel with a two-species test aerosol. The test conditions involved the release of a simulated fission product aerosol, NaI, into the containment atmosphere after the end of a small sodium pool fire. Four organizations made pretest predictions of aerosol behavior using five computer codes. Two of the codes (QUICKM and CONTAIN) were discrete, multiple species codes, while three (HAA-3, HAA-4, and HAARM-3) were log-normal codes which assume uniform coagglomeration of different aerosol species. Detailed test results are presented and compared with the code predictions for eight key aerosol behavior parameters. 11 refs., 44 figs., 35 tabs.
Date: October 1, 1985
Creator: Hilliard, R.K.; McCormack, J.D. & Muhlestein, L.D.
Partner: UNT Libraries Government Documents Department

Large-scale tests of aqueous scrubber systems for LMFBR vented containment

Description: Six large-scale air cleaning tests performed in the Containment Systems Test Facility (CSTF) are described. The test conditions simulated those postulated for hypothetical accidents in an LMFBR involving containment venting to control hydrogen concentration and containment overpressure. Sodium aerosols were generated by continously spraying sodium into air and adding steam and/or carbon dioxide to create the desired Na/sub 2/O/sub 2/, Na/sub 2/CO/sub 3/ or NaOH aerosol. Two air cleaning systems were tested: (a) spray quench chamber, educator venturi scrubber and high efficiency fibrous scrubber in series; and (b) the same except with the spray quench chamber eliminated. The gas flow rates ranged up to 0.8 m/sup 3//s (1700 acfm) at temperatures to 313/sup 0/C (600/sup 0/F). Quantities of aerosol removed from the gas stream ranged up to 700 kg per test. The systems performed very satisfactorily with overall aerosol mass removal efficiencies exceeding 99.9% in each test.
Date: January 1, 1980
Creator: McCormack, J.D.; Hilliard, R.K. & Postma, A.K.
Partner: UNT Libraries Government Documents Department

U. S. position paper on sodium fires, design and testing

Description: Sodium combustion phenomena and U.S. computer codes developed for sodium fires are discussed. Ways of preventing and mitigating sodium fires are described. Effects of sodium fires and spills on LMFBR structural materials, thermal insulation materials, and equipment/instrumentation are considered. (DLC)
Date: May 1, 1982
Creator: Hilliard, R.K.; Johnson, R.P. & Powers, D.A.
Partner: UNT Libraries Government Documents Department

Aerosol behavior during sodium pool fires in a large vessel: CSTF tests AB1 and AB2

Description: Two large-scale aerosol behavior tests, using sodium pool fires as the aerosol source, were performed in the Containment Systems Test Facility (CSTF). The tests were conducted to characterize the properties and behavior of sodium aerosol particles formed and aged in a large containment vessel. The 20-m high, 850-m/sup 3/ CSTF containment building in regard to parameters that affect agglomeration and gravitational settling. In both tests, sodium burned for one hour in a 4.38-m/sup 2/ pool, and the only difference between them was that steam was injected during the second test, simulating the release of water vapor from heated concrete.
Date: June 1, 1979
Creator: Hilliard, R.K.; McCormack, J.D. & Postma, A.K.
Partner: UNT Libraries Government Documents Department

Recent aerosol tests in the Containment Systems Test Facility

Description: The Containment Systems Test Facility (CSTF) is a 20-meter high, 850m/sup 3/ model containment vessel in which various sodium fire aerosol air cleaning tests are studied for purposes of developing and proof testing air cleaning techniques. The first series of tests was designed to study the properties of sodium fire aerosols without any air cleaning and to provide a data base for model verification using large-scale experiments. To date, three such tests (two pool fire and one spray fire) have been completed and are being analyzed. These tests will be discussed, as will plans for the air cleaning tests to follow.
Date: October 1, 1978
Creator: McCormack, J.D.; Hilliard, R.K. & Postma, A.K.
Partner: UNT Libraries Government Documents Department

EVALUATION OF AIR CLEANING SYSTEMS FOR FFTF CONTAINMENT MARGINS

Description: Alternative air cleaning concepts were evaluated for possible application to FFTF containment margins. For evaluation purposes, it was assumed that the air cleaning system must process 3.07 m{sup 3}/s (6500 ACFM) of gas containing sodium compound aerosols (mainly NaOH) at temperatures up to 4070C (7000 F) and pressures up to 0.184 MPa (26.4 psia) and accommodate 5450 kg (12,000 lb) of aerosol material. Three systems designed for 90% efficient removal (a venturi scrubber, a submerged gravel scrubber and a spray scrubber) were compared. The submerged gravel scrubber and the venturi scrubber were rated as prime candidates. Four systems designed for 99% removal efficiency (the two optimum scrubbers chosen for 90% removal efficiency fitted with fibrous elements, a sand and gravel filter and a HEPA filter bank) were compared. The tI~ scrubbers were again rated as prime candidates. Both the sand and gravel filter and the HEPA filter bank were found to be excessively large and costly. Considerable experience supports the use of the optimum scrubber systems and it is concluded that their use is technically feasible for the FFTF containment margins application.
Date: August 1, 1980
Creator: POSTMA, A K. & HILLIARD, R K.
Partner: UNT Libraries Government Documents Department

SUBMERGED GRAVEL SCRUBBER DEMONSTRATION AS A PASSIVE AIR CLEANER FOR CONTAINMENT VENTING AND PURGING WITH SODIUM AEROSOLS -- CSTF TESTS AC7 - AC10

Description: Four large-scale air cleaning tests (AC7 - AC10) were performed in the Containment Systems Test Facility (CS'lF) to demonstrate the performance of a Submerged Gravel Scrubber for cleaning the effluent gas from a vented and purged breeder reactor containment vessel. The test article, comprised of a Submerged Gravel Scrubber (SGS) followed by a high efficiency fiber demister, had a design gas flow rate of 0.47 m{sup 3}/s (1000 ft{sup 3}/min) at a pressure drop of 9.0 kPa (36 in. H{sub 2}O). The test aerosol was sodium oxide, sodium hydroxide, or sodium carbonate generated in the 850-m{sup 3} CSTF vessel by continuously spraying sodium into the air-filled vessel while adding steam or carbon dioxide. Approximately 4500 kg (10,000 lb) of sodium was sprayed over a total period of 100 h during the tests. The SGS/Demister system was shown to be highly efficient (removing ~99.98% of the entering sodium aerosol mass), had a high mass loading capacity, and operated in a passive manner, with no electrical requirement. Models for predicting aerosol capture, gas cooling, and pressure drop are developed and compared with experimental results.
Date: November 1, 1981
Creator: HILLIARD, R K.; MCCORMACK, J D. & POSTMA, A K.
Partner: UNT Libraries Government Documents Department

Preliminary results of CSTF aerosol behavior test, AB-1. [LMFBR]

Description: A large-scale aerosol behavior test (AB-1) was performed in the Containment Systems Test Facility (CSTF) containment vessel using sodium oxide aerosol generated by a pool of sodium burning in air. The purpose was to characterize the aerosol properties and compare the experimental results with computer code predictions. The 20-meter high CSTF vessel is by far the largest ever used in aerosol agglomeration studies and is approximately half-scale of large commercial reactor containment buildings for the parameters affecting particle agglomeration and settling.
Date: October 1, 1977
Creator: Hilliard, R.K.; McCormack, J.D.; Hassberger, J.A. & Muhlestein, L.D.
Partner: UNT Libraries Government Documents Department